1. Field of the Invention
The invention relates in general to a liquid crystal display, and more particularly to a chip-on-glass liquid crystal display.
2. Description of the Related Art
Liquid crystal displays (LCD) have become more and more popular in computer monitors or TVs due to their light weight, flatness and low radiation, compared with the CRT monitor. In addition to improving the display quality of LCDs, such as color, contrast and brightness, the manufacturers try to improve the manufacturing process to reduce the cost and manufacturing time.
The LCD includes a timing controller, source drivers and at least one gate driver to drive its liquid crystal panel. Conventionally, the timing controller is welded on a control print circuit board, the source drivers are welded on an X-board, and the gate driver is welded on a Y-board. The control print circuit board connects to the X-board via flexible printed circuit boards (FPCs), while the X-board and the Y board each connects to the liquid crystal panel via other FPCs. Therefore, the conventional LCD requires at least three boards to be connected to the panel and the manufacturing process is thus complex. In order to simplify the manufacturing process, the chip-on-glass (COG) LCD has been developed.
FIG. 1 is diagram of a conventional COG LCD. The COG LCD 100 includes a panel 110, a plurality of source drivers 112, at least one gate driver 114, a printed circuit board 120 and a plurality of flexible printed circuit boards 130. The source drivers 112 and the gate driver 114 are disposed on the glass substrate of the panel 110 and electrically connected to the printed circuit board 120 via the flexible printed circuit boards 130. The timing controller (not shown in FIG. 1) is disposed on the printed circuit board 120, and outputs image data and control signals to the source drivers 112 and the gate driver 114. In COG LCD 100, only one board (PCB 120), instead of three, is required to connect to the panel 110 via the FPCs 130. Therefore, manufacturing process is simplified.
However, the manufacturing process of COG LCD is still not simplified enough because a plurality of flexible printed circuit boards are needed, and in the above example in FIG. 1, the number of flexible printed circuit boards is 11. The flexible printed boards need a plurality of contact points with the liquid crystal panel and the possibility of electrical contact failure is thus increased.